I. Field of the Invention
This invention relates generally to apparatus for facilitating the repair and refurbishment of damaged surfaces, and more particularly to a kit including a plurality of sandpaper supporting devices which may readily be adapted to conform to the characteristics of the work area to be finished in an abrading operation, the device being either hand operated or machine powered.
II. Discussion of the Prior Art:
In auto body repair or in the repair of fiberglass hulls on marine craft, damaged areas are generally filled with a metal or plastic and, following that, a rotary grinder may be used to grind down the filling material until the original lines or contours are approximated. Following that, a hand sanding operation is generally carried out in repeated steps and with finer and finer grit abrasive paper until the surface being treated is smooth, free of waves and ready for painting.
It has been found difficult to create an acceptable surface when a sheet of sandpaper, either folded or unfolded, is held in the palm of the body repairman's hand and rubbed back and forth across the area being refinished. Any irregularities tend to show up as surface imperfections when the painting has been completed. Irregular patterns often result from hand-held abrasive paper as do waves and finger marks due to the non-uniform pressure being applied. It is also known that sandpaper can be mounted on a sanding block having a planar surface, but oftentimes such blocks are too inflexible to permit the abrasive sheet to conform to the contours of the surface being treated, especially if the surface is curved rather than flat.
Not only should the sanding block be of a predetermined flexibility, but, moreover, blocks of varying width and length dimensions are needed if the labor involved is to be reduced. That is to say, where large surfaces, such as marine hulls, automotive side panels, trunk lids and hoods are involved, a longer and wider sandpaper supporting block may be employed such that larger areas can be abraded in a few passes of the hand sanding apparatus, thus saving on labor costs. Shorter blocks may generally become useful where sharper corners or surface transitions are encountered.
The 3M Company of St. Paul, Minn., is a major supplier of abrasive papers to automobile body shops and marine repair facilities. These sandpapers come in varying grits and generally are dispensed from a roll, the rolls coming in two different width dimensions. The non-abrasive surface of the papers are generally coated with an adhesive, facilitating the securement of the paper to a sanding block. When it becomes necessary to change the paper to obtain a different abrasive grit, it has been the practice in the past to peel off the original length of abrasive paper from the sanding block and then replace it with a new piece having the desired grit. When it is considered that the first piece being replaced may still have from 50% to 90% of useful life and that the environment of a body shop is extremely dusty and dirty, the partially used piece of sandpaper often becomes totally unusable when the adhesive backing becomes coated with dust and dirt so that it cannot be reapplied to the sanding block at a later time. Thus, while it would be advantageous to be able to reuse sandpapers whose abrasive qualities have not been totally used up, this has heretofore been impossible because once the partially used piece of sandpaper has been stripped from its sanding block and allowed to sit in a dusty environment, its adhesive backing loses its tackiness.
Prior art sandpaper supporting blocks also incorporate a variety of styles of handles for facilitating their gripping and manipulation of the sanding blocks during use. For example, for shorter sanding blocks, only a single handle member may be required. Longer sanding blocks, e.g., those about 21/2 feet in length, will generally have two handles spaced along the length dimension of the sanding block. Then, too, the shape of the handle, e.g., its height or contour may vary depending upon the surface or surfaces to be abraded and the desires of the user. With prior art sanding arrangements, it has been necessary to provide a large multiplicity of sanding blocks, given the many permutations and combinations of block length, block width, handle location and handle geometry. This necessitates an inordinately high number of sanding blocks, each equipped with its own handle (or set of handles) to accommodate the variety of contours that may be encountered during a body finishing operation.